Ncert Solutions for Class 9 Science Chapter 12: Improvement in food resources class 9 questions and answers
| Textbook | Ncert |
| Class | Class 9 |
| Subject | Science |
| Chapter | Chapter 12 |
| Chapter Name | Improvement in food resources class 9 ncert solutions |
| Category | Ncert Solutions |
| Medium | English |
Are you looking for Class 9 Science Chapter 12 question answer ? Now you can download Improvement in food resources class 9 questions and answers pdf from here.
In Text Questions Page No: 141
Question 1: What do we get from cereals, pulses, fruits and vegetables?
Answer 1: Cereals are the source of carbohydrates and are the main source of energy.
Pulses provide protein for growth and development.
Vegetables and fruits are loaded with minerals, vitamins, carbohydrates, proteins and fats for overall development.
In Text Questions Page No: 142
Question 1: How do biotic and abiotic factors affect crop production?
Answer 1: Biotic factors such as pests, insects and diseases reduce the crop production. A pest causes damage to our crops by feeding. Weeds also reduce crop productivity by competing with the main crop for nutrients and light.
Similarly, abiotic factors such as temperature, wind, rain etc. affect the net crop production. For example droughts and floods have a great impact on crops sometimes, destroying the entire crop.
Question 2: What are the desirable agronomic characteristics for crop improvements?
Answer 2: Desirable agronomic characteristics for crop improvements are:
(a) Tallness and profuse branching are desirable characters for fodder crops.
(b) Dwarfness is desired in cereals, so that less nutrients are consumed by these crops.
In Text Questions Page No: 143
Question 1: What are macro-nutrients and why are they called macronutrients?
Answer 1: Nutrients that are required by plants in larger quantities for their growth are called macronutrients. There are six macronutrients required by plants – nitrogen, phosphorus, potassium, calcium, magnesium, and Sulphur. Physiological processes including reproduction, growth, and susceptibility to diseases in plants are affected by the deficiency of these nutrients.
Question 2: How do plants get nutrients?
Answer 2: Plants need 16 fundamental nutrients to grow. Water provides carbon and oxygen, while the soil provides the other nutrients.
In Text Questions Page No: 144
Question 1: Compare the use of manure and fertilizers in maintaining soil fertility
Answer 1:
| Aspect | Manure | Fertilizers |
|---|---|---|
| Source | Organic (animal waste, compost, crop residues) | Inorganic or synthetic (chemical compounds) |
| Nutrient Content | Contains a wide range of nutrients, including macro and micronutrients (N, P, K, Ca, Mg, S, and trace elements) | Primarily focused on primary nutrients (N, P, K) and sometimes micronutrients |
| Nutrient Release | Slow, gradual release over time (depends on decomposition rate) | Fast release, providing quick nutrients to plants |
| Effect on Soil | Improves soil structure, water retention, and microbial activity | Can improve nutrient availability but may degrade soil structure over time if used excessively |
| Organic Matter | High in organic matter, enhancing soil texture and biological activity | Little to no organic matter; does not contribute to long-term soil health |
| Environmental Impact | Generally environmentally friendly, but can contribute to greenhouse gases (methane, nitrous oxide) if not managed properly | Can cause nutrient leaching, groundwater pollution, and eutrophication if overused |
| Cost | Can be low-cost if locally sourced or produced, but may require more labor and space for storage | Generally more expensive than manure; easy to apply, but continuous use increases long-term costs |
| Application Frequency | Requires regular application and proper composting for best results | Can be applied more frequently with more precision, but needs proper management to avoid overuse |
| Sustainability | Highly sustainable when sourced locally and applied properly | Less sustainable over the long term if used exclusively without organic amendments |
| Impact on Soil Microbes | Promotes healthy microbial life, improving long-term soil fertility | Can harm soil microorganisms if not applied properly, especially synthetic fertilizers |
| Ease of Use | Requires more effort to apply and manage (e.g., composting) | Easier to apply with modern equipment and more precise application |
In Text Questions Page No: 145
Question 1: Which of the following conditions will give the most benefits? Why?
(a) Farmers use high-quality seeds, do not adopt irrigation or use fertilizers.
(b) Farmers use ordinary seeds, adopt irrigation and use fertilizer.
(c) Farmers use quality seeds, adopt irrigation, use fertilizer and use crop protection measures.
Answer 1: Option (c) will give the most benefits because the use of good quality seeds is not only sufficient until the soil is properly irrigated, enriched with fertilisers and protected from biotic factors.
In Text Questions Page No: 146
Question 1: Why should preventive measures and biological control methods be preferred for protecting crops?
Answer 1: Preventive measures and biological control are not harmful to crops as well as to the environment. They are ecologically safe, target specific and harmless to other organisms.
Question 2: What factors may be responsible for losses of grains during storage?
Answer 2: During the storage of grains, various biotic factors, such as insects, rodents, mites, fungi, bacteria, etc., and various abiotic factors, such as inappropriate moisture, temperature, lack of sunlight, flood, etc., are responsible for the losses of grains. These factors act on stored grains and result in degradation, poor germinability, discolouration, etc.
In Text Questions Page No: 147
Question 1: Which method is commonly used for improving cattle breeds and why?
Answer 1: Cross breeding is a process in which indigenous varities of cattle are crossed by exotic breeds to get a breed which is high yielding. During cross breeding, the desired characters are taken into consideration. The offspring should be high yielding, should have early maturity and should be resistant to climatic conditions.
In Text Questions Page No: 148
Question 1: Discuss the implications of the following statement: “It is interesting to note that poultry is India’s most efficient converter of low fibre food stuff (which is unfit for human consumption) into highly nutritious animal protein food.”
Answer 1: Poultry in India is the most efficient converter of low fibre food stuff into highly nutritious animal protein food. In poultry farming, domestic fowls are raised to produce eggs and chicken. For this, the fowls are given animal feeds in the form of roughage, which mainly consists of fibres. Thus, by feeding animals a fibre rich diet, the poultry gives highly nutritious food in the form of eggs and chicken.
In Text Questions Page No: 148
Question 1: What management practices are common in dairy and poultry farming?
Answer 1: A well-thought-out, hygienic shelter for poultry and birds of prey. Dairy animals, poultry, and birds are given proper, high-quality food and fodder. significance for the prevention and treatment of bacterial, viral, or fungal diseases in animals. Animal shelter that is feasible for sunlight and has good ventilation.
Question 2: What are the differences between broilers and layers and in their management?
Answer 2: Broilers: The poultry bird raised for meat purposes is called a broiler. Broilers feed on protein-rich adequate-fat food. The level of vitamins A and K is kept high in poultry feeds.
Layers: The egg-laying poultry bird is called a layer. The housing, environmental and nutritional requirements of broilers vary from those of egg layers. Layers require proper lighting and enough space.
In Text Questions Page No: 150
Question 1: How are fish obtained?
Answer 1: Fish can be obtained in two ways:
- Capture fishing: It is the process of obtaining fish from natural resources.
- Culture fishery: It is the practice of farming fishes. Farming can be done in both freshwater ecosystem (which includes river water, pond water) and marine ecosystem.
Question 2: What are the advantages of composite fish culture?
Answer 2: Composite fish culture offers several advantages:
- Increased Productivity: By farming different species of fish together, it maximizes the use of water resources and improves overall fish production in a given area.
- Reduced Competition: Different fish species occupy different ecological niches, reducing competition for food and space, which leads to better growth rates.
- Diverse Harvest: Farmers can harvest fish at different times, providing a more consistent income and reducing market risks associated with the availability of one species.
- Better Resource Utilization: Different species utilize different types of food, which helps in efficient use of feed and other resources like water and oxygen.
- Improved Disease Resistance: By combining species with different immune responses, the risk of disease outbreaks affecting all fish in the pond is reduced.
- Efficient Use of Pond Area: The various species can exploit different levels of the water column, maximizing space and resources.
- Sustainability: Composite fish culture promotes ecological balance and can be a more sustainable approach to fish farming by preventing over-exploitation of any single species.
In Text Questions Page No: 150
Question 1: What are the desirable characters of bee varieties suitable for honey production?
Answer 1:
- The variety of bees should yield a large amount of honey.
- The bees should stay for a longer period in bee hives.
- The bees should not sting much.
- Bees should be disease resistant.
Question 2: What is pasturage and how is it related to honey production?
Answer 2: The flowers which are available to the bees for nectar and pollen collection are called pasturage. It is related to the production of honey as the taste and quantity of honey are determined by pasturage.
Exercises
Question 1: Explain any one method of crop production which ensures high yield.
Answer 1: One technique used for high-yield plant breeding is plant breeding, which is done to enhance crop types through plant breeding. Plants with desired traits are selected from a variety of locations, and then hybridization or cross-breeding is carried out among these diversities to produce a crop or plant with the desired qualities.
Question 2: Why are manure and fertilizers used in fields?
Answer 2: They are used to ensure good vegetative growth (leaves, branches and flowers), giving rise to healthy plants, that results in high crop production.
Question 3: What are the advantages of inter-cropping and crop rotation?
Answer 3: Inter-cropping and crop rotation both are used to get maximum benefit on limited land. Inter-cropping helps in preventing pests and diseases to spread throughout the field. It also increases soil fertility, whereas crop rotation prevents soil depletion, increases soil fertility, and reduces soil erosion. Both these methods reduce the need for fertilizers. It also helps in controlling weeds and controls the growth of pathogens and pests in crops.
Question 4: What is genetic manipulation? How is it useful in agricultural practices?
Answer 4: Genetic manipulation is a process in which the transfer of genes takes place from one organism to another. Here, a gene of a particular character is introduced inside the chromosome cell, resulting in a transgenic plant.
Example: BT Cotton is a genetically modified crop which carries bacterial genes that protect this plant from insects. These are used in plants like brinjal, cabbage, rice, cauliflower, and maize crops to get protection from insects.
Question 5: How do storage grain losses occur?
Answer 5: The factors responsible for loss of grains during storage are:
- Abiotic factors like moisture (present in foodgrains), humidity (of air) and temperature.
- Biotic factors like insects, rodents, birds, mites and bacteria.
Question 6: How do good animal husbandry practices benefit farmers?
Answer 6: Cattle farming is one of the methods of animal husbandry that is most beneficial for farmers. Using this method, better breeds of draught animals can be produced. Such draught animals are engaged in agricultural fields for labour work such as carting, irrigation, tilling, etc.
Question 7: What are the benefits of cattle farming?
Answer 7: The benefits of cattle farming are:
- (i) Better quality of milch cattle can be obtained.
- (ii) Good health of draught animals can be maintained
- (iii) New breeds that are resistant to diseases can be produced by crossing two varieties with the desired traits.
Question 8: For increasing production, what is common in poultry, fisheries and bee-keeping?
Answer 8: For increasing production, cross-breeding techniques are used adopted in poultry, fisheries and bee-keeping. Along with these techniques, regular and proper maintenance methods are useful in improving production.
Question 9: How do you differentiate between capture fishing, mariculture and aquaculture?
Answer 9:
| Capture fishing | Mariculture | Aquaculture |
| Fishing is capturing fish from natural resources such as ponds, seas and estuaries. | Commercial culturing of organisms in seawater. Fishing varieties include prawns, oysters, bhetki and mullets. | It produces useful, high-value aquatic plants and animals such as fish, prawns, crayfish, lobsters, crabs, shrimp and seaweeds through the proper use of the country’s available water. This is done in both fresh and salt water. |